This invention relates generally to a biomedical electrode and, more particularly, to a disposable biomedical electrode for establishing electrical contact between a skin portion of the human anatomy and electrical diagnostic equipment.
Many types of disposable biomedical electrodes are known. Typically they comprise an electrically-conductive terminal member having means for electrical connection to electromedical equipment, an adhesive tape or pad for holding the terminal member in place on the skin; and an electrically-conductive, conformable interfacing material such as an electrolyte gel or paste over the surface of the terminal member which contacts the skin to reduce skin impedance and improve electrical contact between the skin and the terminal member. Although prior electrodes function in many applications, they suffer a variety of individual and collective deficiencies such as being difficult to properly orient on the body and failing to provide signals with consistent, repeatable amplitude and frequency parameters.
The invention is a biomedical electrode including a flexible pad having a top surface and a bottom surface; an asymmetrical, linearly aligned array of signal contacts retained by the flexible pad and each having a contact surface projecting from the bottom surface and a coupling surface projecting above the top surface; and a connector including a plurality of connector contacts each being shaped and arranged for electrical connection to a different one of the coupling surfaces. The asymmetrical array of signal contacts facilitates proper positioning of the electrode on the skin.
According to one feature of the invention, the connector further comprises a substrate retaining the connector contacts in an asymmetrical, linearly aligned array geometrically matching the array of signal contacts. The matching arrays facilitate interconnection of the connector contacts and coupling surfaces.
According to other features of the invention, the substrate is a case retaining an amplifier interconnected with the connector contacts, each of the coupling surfaces is defined by a snap contact, each of the connector contacts is a receptacle for receiving one of the snap contacts, and each of the signal contact surfaces is formed by a gel substance. These features provide an efficient, easily employed electrode system.
According to yet another feature of the invention, the bottom surface of the pad is adhesive to facilitate attachment of the electrode to the skin.
According to an additional feature, the electrode includes indicia disposed on the pad and indicating, with respect to an adjacent bundle of muscle fibers, a desired linearly directed orientation for the array of signal contacts.
According to a further feature, the electrode includes indicia disposed on the substrate and indicating, with respect to an adjacent bundle of muscle fibers, a desired linearly directed orientation for said array of connector contacts.
According to other features of the invention, the indicia comprises directional indicators disposed, respectively, on the top surface and the substrate.
According to an additional feature of the invention, the flexible pad includes first and second portions divided by perforations adapted to facilitate separation thereof. The first and second portions can be selectively separated to reduce the size of the electrode for certain applications.
According to still other features of the invention, the first portion is a central portion and retains the signal contacts and the second portion is a marginal portion surrounding the central portion. With this arrangement, the separated central portion functions as a complete electrode.
According to another feature of the invention, the contact surfaces have areas of different size. This feature facilitates the formation of contact surfaces which exhibit desirable equal current density.
According to features of another embodiment, a biomedical electrode includes a flexible pad with adhesive top and bottom surfaces and a linear array of slots, a conductive gel contact retained in each slot and having a contact surface forming a portion of the bottom surface and a coupling surface forming a portion of the top surface, and a connector with connector contacts arranged to engage the coupling surfaces. The adhesive surfaces facilitate assembly of the pad between the connector and a muscle to be monitored.
According to features of yet another embodiment, a biomedical electrode consists of a flexible connector having an adhesive substrate; a plurality of connector contacts projecting from the substrate, each contact formed by a plurality of conductive bristles; and a flexible amplifier retained by the connector and interconnected with the contacts. The flexible connector can be positioned directly on skin covering a muscle to be monitored and the conductive bristles project through hair to insure good electrical contact.